This report contains data and analyses summaries for 12 months of post-disposal monitoring of Alpha Disposal and the North and South Control areas for the "Gulfport Thin-layer Disposal Demonstration Project", from July 1992 through July 1993. The benthic assessment is a portion of the overall suite of studies that is part of a national demonstration program to assess the impacts of thin-layer dredged material disposal for the area of Mississippi Sound adjacent to the Gulfport ship channel. For this project three sites, Alpha, Beta and Delta, received thin-layer disposal material. All three disposal sites were located on the east side of the Gulfport Ship Channel. Data sets based on the analysis of 520 box core samples include: sediment grain size analysis, benthic fauna, and in situ water column parameters, temperature, conductivity, salinity and dissolved oxygen.